Railway signaling



March 14, 1939. l

RAILWAY SIGNALING Filed Aug. 2'7, 1956 3 Sheets-Sheet 1 I IN V TOR George 13. aszerel? av f H13 ATTORNEY March 14, 1 G. R. PFLASTERER RAILWAY SIGNALING Filed Aug; 27, 1936' s sheets-shee 2 T 5 N N R m ow A 8 Y E m H wv Q G NE s E5 7 k3 WMU W wwmmigs w N N Z EB EW X Q MR @Nmfi NR kw k w March 14, 1939,

I G. R. PFLASTERER RAILWAY SIGNALING Filed Aug. 27, 1936' s Sheets-Sheet s Patented Mar. 14, 1939 UNITED STATES PATENT OFFICE RAILWAY SIGNALING Application August 27, 1936, Serial No. 98,211

3 Claims.

My invention relates to railway signaling, and particularly to signaling involving wayside signals located along a trackway for governing the passage of trains.

A feature of my invention is the provision of novel and improved apparatus for establishing a distinctive control for each of three sections in the rear of an occupied section. Each distinctive control is effective to cause a corresponding aspect of the associated wayside signal whereby there 'is produced a three-block, four-indication, system of signaling.

The system provided by this invention is an improvement over that shown and claimed in an application of Howard A. Thompson, for Railway traflic controlling apparatus, filed October 4, 1933, Serial No. 692,155; in an' application of Henry S. Young, for Railway signaling, filed February 27, 1936, Serial No. 66,002;- in'United States Patent No. 2,123,922, issued July 19, 1938, to Leslie R. Allison, for Railway signaling; and in United States Patent No. 2,123,962, issued July 19, 1938, to me, for Railway signaling.

I will describe three forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

Figs. 1A and 1B of the accompanying drawings are diagrammatic views, which when placed end to end inthe order named, illustrate one form of apparatus embodying my invention. Figs. 2 and 3 are diagrammatic views illustrating modifications of a portion of the apparatus shown in Fig. 1A and each also embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1A and 1B, the reference characters I and 8 designate the rails of a stretch of track over which traffic normally moves in the direction indicated by the arrows. The rails! and 8 are divided by insulated joints 9 into track sections W-X, XY, and Y-Z. Each track section is divided into at least two sub-sections IT, 2T, 3T, 4T, etc. Each sub-section is provided with a track battery l9 connected across the rails at one end of the sub-section and with a track relay, designated by the reference character TR with a prefix the same as the numerical prefix of the associated sub-section, connected across the rails at the other end of the sub-section.

To govern the passage of trains through the stretch of railway, a wayside signal designated by a suitable distinguishing reference character, is provided for each track section. Each of these signals includes an upper indication unit U and a lower indication unit L. These units may take any one of several forms of signal mechanism such as semaphore, color light, searchlight, or position light. As here shown, each upper unit U is a color light signal including a stop lamp R capable of displaying a red light, a caution lamp Y capable of displaying a yellow light, and a proceed lamp G capable of displaying a green light; and each lower unit L is a proceed lamp G capable of displaying a greenlight.

For controlling the signals, each section is provided with a polarized direct current neutral relay and with an alternating current undervoltage relay designated by the reference characters HD and LV, respectively, each with a prefix the same 3 as the reference character of the associated signal.

For controlling the relays HD and LV, each section is provided with a pair of line conductors each extending to the signal in advance and each including a front contact of each of the associated track relays. The relays HD are directly connected to the associated pair of line conductors and the relays LV are connected to the associated line'conductors by a transformer designated by the reference character M with a prefix the same as the reference character of the associated signal. As will be explained more in detail hereinafter, the line conductors of each section are at times supplied with alternating current as well as with direct current. The impedance of the polarized relays HD is of such value as will prevent the flow of alternating current in these relays and the resistance of the primary windings M of the transformers M is of such value as will substantially prevent the flow of direct current in these transformers. In addition, condensers Q are interposed in the circuits leading from the line conductors to the primary windings of the transformers M to prevent flow of direct current from the line conductors to the transformers.

For controlling the signal lamps, each section is provided with an approach lighting relay designated by the reference character ER with a prefix the same as the reference character of the associated signal. The relays ER are connected in series with the line conductors for the section next in rear and is therefore energized at all times except when that line circuit is open. That is, the approach lighting relays ER become released only when the section immediately to the rear of the signal with which such relay'is associated becomes occupied by a train. Since the impedance of the relays ER is of such value as will substantially block the passage of alternating current, a resistor l6 for bypassing the alternating current is connected around each relay ER.

The character and direction of the energy supplied to the line conductors for the section next in rear is governed by the relay I-ID associated with the section in advance. That is, theline conductors for such section in the rear are supplied with direct current of normal or reverse polarity according as the relay HD associated with the section in advance is energized or deenergized, respectively, and when the relay HD is;-

energized in the normal direction, the line conductors to the rear are supplied with alternating current simultaneously with direct current in the normal direction.

Each section is provided with a source of direct current, here shown as a battery II, the terminals of which are designated by the reference characters B and C. Y a

For supplying alternating current to the associated line circuit, each section isv provided with a transformer, designated by the. reference character N with a prefix the same as the reference character of the associated signal, having: a primary winding 22 and a secondary winding 23. Each secondary winding 23 is connected in series with the line conductors for the section in the rear.

For supplying alternating current to the primary winding ZZ'ofthe transformers N, each section is provided with a device designated by the reference character'A with a prefix the same as the reference character of the associated signal.

As here shown, each device A is an alternator of the vibrating reed type. Referring to alternator I 3A, for example, anelastic member I! is caused to vibrate between terminals l8 and l9 by a control winding 20. In the deenergized condition of alternator A, member I? does not connect with either terminal H3 or [9 but does connect with a terminal 2!. When energy is supplied to the alternator, winding 2! will attract member I! causing it to connect with terminal l9 and to move away from terminal 2|" thereby causing winding 20' to become deenergized. Upon the deenergization of winding 20, the resilience of member I! will cause it' to move away from terminal l9 and to connect with terminal 8 as well as with terminal 2i. The circuit for winding 20 being then again completed through terminal 2!, winding 2ll'will again attract member l! causing the cycle of operation just described to be completed. Winding 20, therefore, will be repeatedly energized and deenergized as long as energy is supplied to its control circuit. When member I! is in engagement with contact I 8, the left-hand portion of primary winding 22 of transformer I3N will be energized in one direction whereas, when member IT is in engagement with contact IS, the right-hand portion of primary winding 22 will be energized in the reverse direction. Alternating current, therefore, will be induced in secondary winding 23 of transformer I3N as long as alternator l-3A is operating.

The polarized direct current relays HB and. the alternating current low voltage relays LV control the signals in the following manner: When relay HD is deenergized (see signal IS), a circuit is established for the stop lamp R of the upper unit U so that when relay lER becomes released, the signal will display a red light toindicate stop. This circuit may be traced from terminal B through back contact 26 of relay lSER, back point of contact 2'! of relay IEHD, and lamp R to terminal C. When relay HD is energized in the reverse direction (see signal I4) a. circuit is established for the caution lamp Y of the upper unit U so that when relay MER becomes released, the signal will display a yellow light to indicate approach next signal prepared to stop. The circuit for lamp Y may be traced from terminal B through back contact 28 of relay MER, front point of contact 29 of relay I 4 HD, the reverse polar contact 303l of relay MED, and lamp Y toterminal C. When relay HD is energized in the normal direction (see signal I3), a circuit for the" proceed lamp G of the upper unit U is established so that, when relay IBER becomes released, the signal--Will display a single green light to. indicate approach next signal at medium speed. The circuit for lamp G of the upper unit U may be traced from terminal B through back contact 32 of relay I3ER, front point of contact 33' of relay l3HD, normal polar contact 3034 of: relay I3HD, and lamp G to terminal. C. When the line circuit is supplied'with alternating current simultaneously with direct current in the normal direction (see signal l2) the releasing of relay IZER will close the previously traced circuit for the lamp G of the upper unit U and relay IZLV will become energized by secondary winding 25 of transformer IZM to close a circuit for the lamp G of the lower unit L over front contact 35 of relay lZLV so that the signal will display a green light over a green light to indicate proceed at normal'speed.

As here shown, a train K is indicated diagrammatically in the section immediately to the right of location Z so that relay IEI-ID is deenergized to cause signal 15 to assume the condition for the display of the stop indication. Since relay I'5H2D is deenergized, relay MHD is energized in the reverse direction over a path which passes from terminal B of battery I l at signal I 5 through resistor l6 and relay IEER in multiple, back point of contact All of relay RSI-ID, secondary winding 23 of transformer 'I5N', front point of contact 4| of relay BTR, front point of contact 42 of relay 5TB, relay MHD, front contact lliof relay 5TB, front contact M of relay 6TB, and back point of contact 45 of relay I 5HD to terminal C of battery ll. Since relay MHD is energized, relay l'eI-ID is energized in the normal direction over a path which passes from terminal B of battery H at signal 14 through resistor 58 and relay MER in multiple, front point of contact MS of relay MHD, front contact 4'! of relay 4TB, front contact 48 of relay 3TB, relay lSI-ID. front contact 42 of relay 3TB, frontcontact 59 of relay 4TB, secondary winding 23 of transformer N, and front point of contact 5! of relay NEED to terminal 0 of battery H.

Since relay IBHD is energized in the normal direction, relay lZI-ID is energized in the normal direction over a path similar to that just traced for the relay lZiHD and the operation of alternator MA is initiated to supply alternating current to transformer IZN. The circuit for alternator ISA passes from terminal B of front contact 52 of relay 8 3H1), normal polar contact 5354 of relay ISHD, and alternator |3A to terminal G. Since alternator l3A is operating, transformer l 2M is energized with alternating current which passesover a path from one terminal of secondary winding 23 of transformer ISN through front point of contact 55 of relay I3HD, battery ll atsignal l3, resistor l6 and relay I 3ER in multiple, front point of contact 56 of relay I3HD, front contact 51 of relay 2TB, front contact 58 of relay ITR, front contact 59 of relay IZHD, normal polar contact GIL-6| of relay I ZHD, back contact 62 of relay I2ER, primary winding 24 of transformer I2M, condenser IZQ, front contact 63 of relay TR, and front contact 64 of relay 2TB to the other terminal of secondary winding 23 of transformer I3N. A circuit therefore is established for primary winding 24 of transformer I2N so that, when relay IZER, becomes released to close its back contact 62, energy will be induced in secondary winding 25 of transformer I2N to cause relay I2LV to become energized. 1

It will be readily apparent that the proceed lamps G of the lower unit could be connected} directly to secondary winding 25 of the associated transformer M, thereby eliminating the low voltage relays LV. The relays LV, however, are provided to insure against the possibility of the associated lamp G becoming partially energized by foreign current of a voltage lower than the normal lamp voltage which current may be induced in the line conductors from, for example, an adjacent transmission line.

The relays HD are provided with a retained neutral characteristic in order to avoid tumbledown of signal control circuits to the rear during pole changing periods. For example, when the train K passes out of the section immediately to the right of location Z 5-0 that the energization of the relay I Iii-ID is changed from the reverse direction to the normal direction, front points of contacts 46 and 5| of relay MHD remain closed so that the energization of the line conductors for the section X-Y is not disturbed.

Referring next to Fig. 2, I have shown herein one signal and associated apparatus which, when included in a system with wires 10 and H at the right connected to wires 12 and 13, respectively, at the left, will provide a three-block, four-indication, system of signaling similar to that described for the system shown in Figs. 1A and 1B. The principal difference between the system illustrated in Fig. 2 and the system illustrated in Figs. 1A and 1B is in the indications displayed by the signal. That is, in Fig. 2, the normal proceed indication is a single green light and the approach next signal at medium speed indication is a yellow light over a yellow light, whereas in Figs. 1A and 1B the normal proceed indication is a green light over a'green light and the approach next signal at medium speed indication is a single green light.

The relay HD controls the lamps of the upper unit U in a manner similar to that described for the system shown in Figs. 1A and 13. That is, the stop lamp R becomes energized when the relay HD is deenergized and the caution lamp Y or proceed lamp G becomes energized when the relay HD is energized in the reverse direction or the normal direction, respectively. The caution lamp Y of the lower unit L receives energy direct from the line conductors of the forward section through the usual transformer M, while a condenser Q is interposed in the circuit leading to the primary winding 24 of the transformer M to prevent flow of direct current from the line conductors to the transformer.

Connected in series with the lamp Y of the lower unit L is an alternating current relay designated by the reference character LY and connected in series with the caution lamp Y of the upper unit U is a direct current relay designated by the reference character UY.

The relays HD, LY, and UY control the energy supplied to the line conductors for the rear section in the following manner: When the relay HD is deenergized, the line conductors for the rear section will be supplied with direct current in the reverse direction over the back points of contacts 14 and 15 of relay I-lD. When relay HD is energized in the reverse direction and the relay LY is deenergized, the line conductors for the rear section will be supplied with direct current energy in the reverse direction and the operation of the alternator A will be initiated. The path for the direct current energy includes front points of contacts 74 and E5 of relay HD, reverse polar contacts 16-'il and 18-19 of relay HD, and back points of contacts 89 and 8! of relay LV. The circuit for alternator A passes from terminal B over back point of contact 82 of relay LV, front contact 83 of relay I-ID, reverse polar contact 84-435 of relay HD, and alternator A to terminal C. The path for supplying alternating current to the rear line circuit includes secondary winding 23 of transformer N and front points of contacts 14 and T5 of relay HD. When relay HD is energized in the reverse direction and both relays LY and UY are energized, the line conductors for the rear section will be supplied with direct current in the normal direction over a path which includes front points of contacts 14 and 15 of relay Ifl), reverse polar contacts. 'I6Tl and 18-19 of relay HD, front points of contacts and 3! of relay LY, and front points of contacts 85 and 8'! of relay UY. When relay HD is energized in the normal direction, as shown in the drawings, the line conductors for the rear section are energized by direct current in the normal direction over front points of contacts 14 and 15 of relay HD and normal polar contacts It-J8 and 18-89 of relay HD.

It will be noted that, when the relay HD is energized in the reverse direction, both relays LY and UY must be energized before the rear line circuit can be supplied with energy in the normal direction to cause the signal (not shown) controlled by that line circuit to display the normal proceed indication. Since the relays LY and UY are connected in series with the caution lamps Y of the lower unit and upper unit, respectively, this feature insures that the filaments of both lamps must be intact before a proceed indication can be displayed at the signal next in rear.

Furthermore, if either lamp Y fails to become illuminated when traffic conditions are such that both lamps should be lighted, that is, if the signal is displaying one yellow light to indicate approach next signal prepared to stop when it should be displaying two yellow lights to indicate approach next signal at medium speed, then the rear line circuit will be conditioned so that the signal (not shown) controlled by that line circuit will be displaying two yellow lights to indicate approach next signal at medium speed.

UY becomes released when both lamps Y should be illuminated, the rear line circuit will be supplied with direct current in the reverse direction and the operation of alternator A will be initiated so that alternating current also will be supplied to the rear line circuit. The circuit for alternator A may be traced from terminal B through back contact of relay UY, front point of contact 82 of relay LY, front contact 83 of For example, if lamp Y of the upper unit U should become burned out so that relay relay HD, reverse polar contact 84-85 of relay HD, and alternator A to terminal C. The path for supplying direct current in the reverse direction to the rear line circuit includes back points of cotacts 88 and 81 of relay UY, front points of contacts and BI of relay LY, reverse polar contacts 'l6-Tl and 18l9 of relay HD, and front points of contacts 14 and 15 of relay HD. Alternating current will be supplied to the rear line circuit over the usual path which includes secondary winding 23 of transformer N and front points of contacts 14 and 15 of relay HD. The rear line circuit, therefore, will be energized with direct current in the reverse direc tion as well as with alternating current so that a signal which may be controlled by such line circuit will be in condition to display a yellow light over a yellow light to indicate approach next signal at medium speed.

Referring now to Fig. 3, I have shown herein one signal and associated apparatus which when connected in a system will provide three-block, four-indication, signaling similar to that described for the system shown in Figs. 1A and 1B. The principal difference between the system illus trated in Fig. 3 and the system illustrated in Figs. 1A and 1B is that in Fig. 3 the signal is controlled directly over the track rails, thereby dispensing with the necessity for the use of line conductors. A polarized track relay TR connected to the rails of the forward section controls the lamp circuits for the upper unit U and the energy supplied to the rails of the rear section in the usual manner. That is, the stop lamp R will be energized when the relay TR becomes deenergized to close back point of contact iii of relay TR and the caution and proceed lamps will be energized, when front point of contact Si is closed, according as the relay TR is energized in the reverse and normal directions to close polar contacts 9293 and 92-94, respectively. The rails of the rear section are supplied with direct current energy from a track battery TB in the normal and reverse directions according as the relay TR is energized or deenergized to close contacts 95-and 96 at their front or back points, respectively. When the relay TR is energized in the normal direction, as shown, the operation of alternator A is initiated so that alternating current will be supplied to the rails of the rear section simultaneously with direct current. The circuit for alternator A includes front contact 91 and normal polar contact 98-99.

The transformer M controls the proceed lamp G of the lower unit L in the usual manner. That is, secondary winding 25 is connected direct to the lamp G and primary winding 24 is connected over a front contact of the relay TR and condenser Q to the rails of the forward section. The condenser Q is provided to prevent the flow of direct current in the primary winding 24.

The relay TR is provided with a retained neutral characteristic for the usual purpose, that is, to avoid tumble-down from the signal control circuits to the rear during pole changing periods. This feature also insures against a momentary energization of the stop lamp R during such periods of change in polarity.

In view of the similarity of the operation of the apparatus shown in Fig. 3 to the operation of the apparatus shown in Figs. 1A and IE, it is believed that further detailed description is unnecessary.

Although I have herein shown and described only three forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, What I claim is: a

1. In combination, a forward and a rear section of railway track, a signal for the forward section including a first lamp and a second lamp, means effective when the forward section is unoccupied to light only said first lamp or to light both said lamps in accordance with traffic conditions in advance of the forward section, a first relay connected in series with said first lamp, a second relay connected in series with said second lamp, a pair of conductors for the rear section governed by traflic conditions in that section, and means including contacts of said first and, said second relays for controlling the character and direction of the energy supplied to said pair of conductors.

2. In combination, a forward and a rear section of railway track, a signal for the forward section including a first lamp and a second lamp, means effective when the forward section is unoccupied to light only said first lamp or to light both said lamps in accordance with traffic conditions in advance of the forward section, a first relay connected in series with said first lamp, a second relay connected in series with said second lamp, a pair of conductors for the rear section governed by traiiic conditions in that section, means effective when both said first and said second relays are energized to supply said pair of conductors with only current of one character, and means effective when either of said relays is deenergized to supply said pair of conductors with current of another character simultaneously with current of said one character.

3. In combination, a forward and a rear section of railway track, a signal for the forward section including a first lamp and a second lamp, means eifective when the forward section is unoccupied to light only said first lamp or to light both said lamps in accordance with trafiic conditions in advance of the forward section, a first relay connected in series with said first lamp, a

second relay connected in series with said second lamp, a pair of conductors for the rear section governed by traflic conditions in that section, means effective when both said first and said second relays are energized to supply said pair of conductors with only direct current in one direction, and means effective when either of said relays is deenergized to supply said pair of conductors with alternating current simultaneously with direct current in the other direction.

GEORGE R. PFLASTERER.

Cir 

